1
|
Sachan S, Moya CG, Voigt B, Köhn M, Balbach J. The pro-sequence of parathyroid hormone prevents premature amyloid fibril formation. FEBS Lett 2023; 597:995-1006. [PMID: 36700832 DOI: 10.1002/1873-3468.14587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/16/2023] [Indexed: 01/27/2023]
Abstract
The parathyroid hormone (PTH) regulates the calcium and phosphate level in blood after secretion from parathyroid chief cells. The pre- and pro-sequences of precursor preproPTH get cleaved during PTH maturation. In secretory granules, PTH forms functional amyloids. Using thioflavin T fibrillation assays, circular dichroism, NMR spectroscopy, and cellular cAMP activation, we show that the pro-sequence prevents premature fibrillation by impairing primary nucleation because of Coulomb repulsion of positively charged residues. Under seeding or high salt conditions or in the presence of heparin at pH 5.5, proPTH fibril formation is delayed, but the monomer release properties are conserved. ProPTH can still activate in cellulo PTH receptor 1 but with impaired potency. These findings give some perspectives on medical applications of PTH in hormone therapy.
Collapse
Affiliation(s)
- Shubhra Sachan
- Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany
| | - Celia González Moya
- Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany
| | - Bruno Voigt
- Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany
| | - Marcel Köhn
- Medical Faculty, Martin-Luther-University Halle-Wittenberg, Germany
| | - Jochen Balbach
- Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany
| |
Collapse
|
2
|
Stefanovic B, Stefanovic L, Manojlovic Z. Imaging of type I procollagen biosynthesis in cells reveals biogenesis in highly organized bodies; Collagenosomes. Matrix Biol Plus 2021; 12:100076. [PMID: 34278289 PMCID: PMC8261018 DOI: 10.1016/j.mbplus.2021.100076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 10/26/2022] Open
Abstract
Mechanistic aspects of type I procollagen biosynthesis in cells are poorly understood. To provide more insight into this process we designed a system to directly image type I procollagen biogenesis by co-expression of fluorescently labeled full size procollagen α1(I) and one α2(I) polypeptides. High resolution images show that collagen α1(I) and α2(I) polypeptides are produced in coordination in discrete structures on the ER membrane, which we termed the collagenosomes. Collagenosomes are disk shaped bodies, 0.5-1 μM in diameter and 200-400 nm thick, in the core of which folding of procollagen takes place. Collagenosomes are intimately associated with the ER membrane and their formation requires intact translational machinery, suggesting that they are the sites of nascent procollagen biogenesis. Collagenosomes show little co-localization with the COPII transport vesicles, which export type I procollagen from the ER, suggesting that these two structures are distinct. LARP6 is the protein which regulates translation of type I collagen mRNAs. The characteristic organization of collagenosomes depends on binding of LARP6 to collagen mRNAs. Without LARP6 regulation, collagenosomes are poorly organized and the folding of α1(I) and α2(I) polypeptides into procollagen in their cores is diminished. This indicates that formation of collagenosomes is dependent on regulated translation of collagen mRNAs. In live cells the size, number and shape of collagenosomes show little change within several hours, suggesting that they are stable structures of type I procollagen biogenesis. This is the first report of structural organization of type I collagen biogenesis in collagenosomes, while the fluorescent reporter system based on simultaneous imaging of both type I collagen polypeptides will enable the detailed elucidation of their structure and function.
Collapse
Affiliation(s)
- Branko Stefanovic
- Department of Biomedical Sciences and Translational Science Laboratory, College of Medicine, Florida State University, 1115 West Call Street, Tallahassee, FL 32306, USA
| | - Lela Stefanovic
- Department of Biomedical Sciences and Translational Science Laboratory, College of Medicine, Florida State University, 1115 West Call Street, Tallahassee, FL 32306, USA
| | - Zarko Manojlovic
- Keck School of Medicine of University of Southern California, 1450 Biggy Street, NRT 4510, Los Angeles, CA 90033, USA
| |
Collapse
|
3
|
Mao M, Alavi MV, Labelle-Dumais C, Gould DB. Type IV Collagens and Basement Membrane Diseases. CURRENT TOPICS IN MEMBRANES 2015; 76:61-116. [DOI: 10.1016/bs.ctm.2015.09.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
4
|
Parsons CJ, Stefanovic B, Seki E, Aoyama T, Latour AM, Marzluff WF, Rippe RA, Brenner DA. Mutation of the 5'-untranslated region stem-loop structure inhibits α1(I) collagen expression in vivo. J Biol Chem 2010; 286:8609-8619. [PMID: 21193410 DOI: 10.1074/jbc.m110.189118] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Type I collagen is a heterotrimeric extracellular matrix protein consisting of two α1(I) chains and one α2(I) chain. During liver fibrosis, activated hepatic stellate cells (HSCs) are the major source of the type I collagen that accumulates in the damaged tissue. Expression of α1(I) and α2(I) collagen mRNA is increased 60-fold compared with quiescent stellate cells and is due predominantly to post-transcriptional message regulation. Specifically, a stem-loop structure in the 5'-untranslated region of α1(I) collagen mRNA may regulate mRNA expression in activated HSCs through its interaction with stem-loop binding proteins. The stem-loop may also be necessary for efficient production and folding of the type I collagen heterotrimer. To assess the role of the stem-loop in type I collagen expression in vivo, we generated a knock-in mouse harboring a mutation that abolished the stem-loop structure. Heterozygous and homozygous knock-in mice exhibited a normal phenotype. However, steady-state levels of α1(I) collagen mRNA decreased significantly in homozygous mutant MEFs as well as HSCs; intracellular and secreted type I collagen protein levels also decreased. Homozygous mutant mice developed less liver fibrosis. These results confirm an important role of the 5' stem-loop in regulating type I collagen mRNA and protein expression and provide a mouse model for further study of collagen-associated diseases.
Collapse
Affiliation(s)
| | - Branko Stefanovic
- the Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32306-4300, and
| | - Ekihiro Seki
- the Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California 92093
| | - Tomonori Aoyama
- the Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California 92093
| | | | | | - Richard A Rippe
- the Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7080
| | - David A Brenner
- the Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California 92093.
| |
Collapse
|
5
|
Pace JM, Wiese M, Drenguis AS, Kuznetsova N, Leikin S, Schwarze U, Chen D, Mooney SH, Unger S, Byers PH. Defective C-propeptides of the proalpha2(I) chain of type I procollagen impede molecular assembly and result in osteogenesis imperfecta. J Biol Chem 2008; 283:16061-7. [PMID: 18375391 DOI: 10.1074/jbc.m801982200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type I procollagen is a heterotrimer composed of two proalpha1(I) chains and one proalpha2(I) chain, encoded by the COL1A1 and COL1A2 genes, respectively. Mutations in these genes usually lead to dominantly inherited forms of osteogenesis imperfecta (OI) by altering the triple helical domains, but a few affect sequences in the proalpha1(I) C-terminal propeptide (C-propeptide), and one, which has a phenotype only in homozygotes, alters the proalpha2(I) C-propeptide. Here we describe four dominant mutations in the COL1A2 gene that alter sequences of the proalpha2(I) C-propeptide in individuals with clinical features of a milder form of the disease, OI type IV. Three of the four appear to interfere with disulfide bonds that stabilize the C-propeptide conformation and its interaction with other chains in the trimer. Cultured cells synthesized proalpha2(I) chains that were slow to assemble with proalpha1(I) chains to form heterotrimers and that were retained intracellularly. Some alterations led to the uncharacteristic formation of proalpha1(I) homotrimers. These findings show that the C-propeptide of proalpha2(I), like that of the proalpha1(I) C-propeptide, is essential for efficient assembly of type I procollagen heterotrimers. The milder OI phenotypes likely reflect a diminished amount of normal type I procollagen, small populations of overmodified heterotrimers, and proalpha1(I) homotrimers that are compatible with normal skeletal growth.
Collapse
Affiliation(s)
- James M Pace
- Department of Pathology, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Terentiev AA, Moldogazieva NT. Cell adhesion proteins and α-fetoprotein. Similar structural motifs as prerequisites for common functions. BIOCHEMISTRY (MOSCOW) 2007; 72:920-35. [DOI: 10.1134/s0006297907090027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
7
|
Khoshnoodi J, Cartailler JP, Alvares K, Veis A, Hudson BG. Molecular recognition in the assembly of collagens: terminal noncollagenous domains are key recognition modules in the formation of triple helical protomers. J Biol Chem 2006; 281:38117-21. [PMID: 17082192 DOI: 10.1074/jbc.r600025200] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The alpha-chains of the collagen superfamily are encoded with information that specifies self-assembly into fibrils, microfibrils, and networks that have diverse functions in the extracellular matrix. A key self-organizing step, common to all collagen types, is trimerization that selects, binds, and registers cognate alpha-chains for assembly of triple helical protomers that subsequently oligomerize into specific suprastructures. In this article, we review recent findings on the mechanism of chain selection and infer that terminal noncollagenous domains function as recognition modules in trimerization and are therefore key determinants of specificity in the assembly of suprastructures. This mechanism is also illustrated with computer-generated animations.
Collapse
Affiliation(s)
- Jamshid Khoshnoodi
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232-2372, USA
| | | | | | | | | |
Collapse
|
8
|
Xu Y, McDonald J, Perloff E, Butticè G, Schreiber BM, Smith BD. Collagen and major histocompatibility class II expression in mesenchymal cells from CIITA hypomorphic mice. Mol Immunol 2006; 44:1709-21. [PMID: 16982097 DOI: 10.1016/j.molimm.2006.07.294] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 07/27/2006] [Accepted: 07/28/2006] [Indexed: 11/23/2022]
Abstract
Major histocompatibility class II (MHC II) transactivator (CIITA) is critical for interferon-gamma (IFN-gamma)-induced repression of collagen [Xu, Y., Wang, L., Buttice, G., Sengupta, P.K., Smith, B.D., 2004. Major histocompatibility class II transactivator (CIITA) mediates repression of collagen (COL1A2) transcription by interferon gamma (IFN-gamma). J. Biol. Chem. 279, 41319-41332] and activation of MHC II transcription. To better understand the role of CIITA and IFN-gamma induced repression of collagen, mesenchymal cells (lung fibroblasts, adventitial fibroblasts, and smooth muscle cells) were isolated from a CIITA deficient mouse (C2ta(tm1Ccum)). IFN-gamma induced MHC II expression and repressed collagen type I expression in all three cell types isolated from the wild type background. As expected, IFN-gamma treatment of cells isolated from CIITA deficient mice did not induce MHC II production or activate the MHC II promoter. Interestingly, collagen gene expression and promoter activity was similar to that of wild type. Moreover, IFN-gamma induced CIITA mRNA and a truncated form of CIITA protein in all cells isolated from CIITA deficient mice. Most importantly, truncated CIITA occupied the collagen alpha 2(I) gene (col1a2) transcription start site during IFN-gamma treatment, but it did not occupy the MHC II promoter as judged by chromatin immunoprecipitation assays. Exogenous expression of a similar truncated form of CIITA maintained its ability to repress col1a2 transcription, but lost its ability to activate MHC II gene transcription suggesting a role for the CIITA C-terminal domain in activation, but not repression. IFN-gamma induced primarily types I and IV CIITA isoforms in the mouse cells. All three isoforms of CIITA were capable of repressing col1a2 and activating MHC II gene transcription. These data suggest that the previously described CIITA knockout mouse carries a hypomorphic mutation, rather than a null mutation. The removal of the leucine rich region in CIITA blocks activation of MHC II without altering repression of collagen transcription.
Collapse
Affiliation(s)
- Yong Xu
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | | | | | | | | | | |
Collapse
|
9
|
Malone JP, Alvares K, Veis A. Structure and Assembly of the Heterotrimeric and Homotrimeric C-Propeptides of Type I Collagen: Significance of the α2(I) Chain. Biochemistry 2005; 44:15269-79. [PMID: 16285730 DOI: 10.1021/bi0508338] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Assembly of the type I procollagen molecule begins with interactions among the C-pro alpha1(I) and C-pro alpha2(I) domains. The C-propeptide domains themselves have subdomains of distinct structures. The important questions are where chain association begins and the basis of the chain selectivity which leads to the preferential formation of the [C-pro alpha1(I)]2[C-pro alpha2(I)] heterotrimer. These questions are addressed by energy minimization modeling of the individual C-propeptide structures, study of their docking interactions, and comparison of the heterotrimeric and homotrimeric C-pro structures and stability. The comparisons show the remarkable impact of the C-pro alpha2 chain on the structure of the assembled trimeric C-propeptide. In the modeling, the three chains were anchored and registered by a short C-terminal collagen triple-helical segment followed by the C-telopeptides in their docked conformation, and then the remaining C-propeptide chains were allowed to interact and dock. Surprisingly, propeptide trimerization did not proceed through the previously proposed N-terminal "oligomerization domain" of the C-propeptide [McAlinden et al. (2003) J. Biol. Chem. 278, 42200] but rather in the most C-terminal domains of type I procollagen chains. Molecular dynamics showed heterotrimer assembly to begin with dimer formation between globular G2alpha2 and the G2alpha1(2) domains followed by trimerization at the G1 domains. Assembly initiation in the putative oligomerization coiled-coil domain is not possible because of the Pro residues at positions 3, 7, and 11 at the N-terminus of the alpha2 C-propeptide chain. To confirm the computations and proposed assembly pathway, the G2alpha1 and G2alpha2 domains were prepared recombinantly as the maltose binding protein constructs, and their interactions were studied by dynamic light scattering and gel filtration chromatography. Under the conditions examined MBP remained as monomer, MBP-G2alpha1 and MBP-G2alpha2 alone formed dimers, but a 2:1 mixture of MBP-G2alpha1 and MBP-G2alpha2 favored trimer formation. Thus, the C-terminal globular domains (G2) of the type I collagen C-propeptides play a crucial role in the initiation of intermolecular assembly and heterotrimer selectivity.
Collapse
Affiliation(s)
- James P Malone
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | | | | |
Collapse
|
10
|
Zankl A, Zabel B, Hilbert K, Wildhardt G, Cuenot S, Xavier B, Ha-Vinh R, Bonafé L, Spranger J, Superti-Furga A. Spondyloperipheral dysplasia is caused by truncating mutations in the C-propeptide of COL2A1. Am J Med Genet A 2005; 129A:144-8. [PMID: 15316962 DOI: 10.1002/ajmg.a.30222] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The term "spondyloperipheral dysplasia" (SPD) has been applied to the unusual combination of platyspondyly and brachydactyly as observed in a small number of individuals. The reported cases show wide clinical variability and the nosologic status and spectrum of this condition are still ill defined. Zabel et al. [1996: Am J Med Genet 63(1):123-128] reported an individual with short stature and SPD who was heterozygous for a frameshift mutation in the C-propeptide domain of COL2A1. To explain the additional finding of brachydactyly that is not an usual feature of the type II collagenopathies, it was postulated that the nature of the mutation induced precocious calcification and premature fusion of metacarpal and phalangeal growth plates. The C-propeptide of collagen II had previously been found to promote calcification ("chondrocalcin"). We have ascertained two further individuals with clinical and radiological findings of a type II collagenopathy in infancy who developed brachydactyly type E like changes of fingers and toes in childhood. In both individuals, heterozygosity for novel, distinct mutations in the C-propeptide coding region of COL2A1 were found. Although all three mutations (the one previously reported and the two novel ones) predict premature termination, their location close to the 3'-end of the mRNA probably protects them from nonsense-mediated decay and allows for synthesis of mutant procollagen chains. However, loss of crucial cysteine residues or other sequences essential for trimerization prevents these chains from associating and participating in procollagen helix formation, and thus leads to accumulation in the ER-consistent with EM findings. The mechanism leading to precocious fusion of phalangeal epiphyses remains to be explored. The consistency of clinical, radiographic, and molecular findings in these three unrelated individuals confirms SPD as a distinct nosologic entity. The diagnosis of SPD is suggested by the appearance of brachydactyly in a child who has clinical and radiographic features of a collagen II disorder.
Collapse
Affiliation(s)
- Andreas Zankl
- Department of Pediatrics, Division of Molecular Pediatrics, University of Lausanne, Lausanne, Switzerland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Fernandes RJ, Seegmiller RE, Nelson WR, Eyre DR. Protein consequences of the Col2a1 C-propeptide mutation in the chondrodysplastic Dmm mouse. Matrix Biol 2004; 22:449-53. [PMID: 14614991 DOI: 10.1016/s0945-053x(03)00077-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Disproportionate micromelia (Dmm) mouse has a three nucleotide deletion in Col2a1 in the region encoding the C-propeptide which results in the substitution of one amino acid, Asn, for two amino acids, Lys-Thr. Western blot and immunohistochemical analyses failed to detect type II collagen in the cartilage matrix of the homozygous mice and showed reduced levels in the matrix of heterozygous mice. Type II collagen chains localized intracellularly within the chondrocytes of homozygote and heterozygote tissues. These findings provide evidence that the expression of type II procollagen chains containing the defective C-propeptide results in an intracellular retention and faulty secretion of type II procollagen molecules. A complete absence of mature type II collagen from the homozygote cartilage and an insufficiency of type II collagen in the heterozygote cartilage explains the Dmm mouse phenotype. The integrity of the C-propeptide is thus crucial for the biosynthesis of normal type II collagen by chondrocytes.
Collapse
Affiliation(s)
- Russell J Fernandes
- Orthopaedic Research Laboratories, Department of Orthopaedics and Sports Medicine, Box 356500, University of Washington, Seattle, WA 98195, USA.
| | | | | | | |
Collapse
|
12
|
Bernocco S, Finet S, Ebel C, Eichenberger D, Mazzorana M, Farjanel J, Hulmes DJ. Biophysical characterization of the C-propeptide trimer from human procollagen III reveals a tri-lobed structure. J Biol Chem 2001; 276:48930-6. [PMID: 11684689 DOI: 10.1074/jbc.m108611200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Procollagen C-propeptide domains direct chain association during intracellular assembly of procollagen molecules. In addition, they control collagen solubility during extracellular proteolytic processing and fibril formation and interact with cell surface receptors and extracellular matrix components involved in feedback inhibition, mineralization, cell growth arrest, and chemotaxis. At present, three-dimensional structural information for the C-propeptides, which would help to understand the underlying molecular mechanisms, is lacking. Here we have carried out a biophysical study of the recombinant C-propeptide trimer from human procollagen III using laser light scattering, analytical ultracentrifugation, and small angle x-ray scattering. The results show that the trimer is an elongated molecule, which by modeling of the x-ray scattering data appears to be cruciform in shape with three large lobes and one minor lobe. We speculate that each of the major lobes corresponds to one of the three component polypeptide chains, which come together in a junction region to connect to the rest of the procollagen molecule.
Collapse
Affiliation(s)
- S Bernocco
- Institut de Biologie et Chimie des Protéines, CNRS UMR 5086, Université Claude Bernard Lyon 1, 69367 Lyon cedex 7, France
| | | | | | | | | | | | | |
Collapse
|
13
|
Olsen DR, Leigh SD, Chang R, McMullin H, Ong W, Tai E, Chisholm G, Birk DE, Berg RA, Hitzeman RA, Toman PD. Production of human type I collagen in yeast reveals unexpected new insights into the molecular assembly of collagen trimers. J Biol Chem 2001; 276:24038-43. [PMID: 11279215 DOI: 10.1074/jbc.m101613200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Substantial evidence supports the role of the procollagen C-propeptide in the initial association of procollagen polypeptides and for triple helix formation. To evaluate the role of the propeptide domains on triple helix formation, human recombinant type I procollagen, pN-collagen (procollagen without the C-propeptides), pC-collagen (procollagen without the N-propeptides), and collagen (minus both propeptide domains) heterotrimers were expressed in Saccharomyces cerevisiae. Deletion of the N- or C-propeptide, or both propeptide domains, from both proalpha-chains resulted in correctly aligned triple helical type I collagen. Protease digestion assays demonstrated folding of the triple helix in the absence of the N- and C-propeptides from both proalpha-chains. This result suggests that sequences required for folding of the triple helix are located in the helical/telopeptide domains of the collagen molecule. Using a strain that does not contain prolyl hydroxylase, the same folding mechanism was shown to be operative in the absence of prolyl hydroxylase. Normal collagen fibrils were generated showing the characteristic banding pattern using this recombinant collagen. This system offers new opportunities for the study of collagen expression and maturation.
Collapse
Affiliation(s)
- D R Olsen
- Cohesion Technologies Inc., Palo Alto, California 94303, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Campbell BG, Wootton JA, Macleod JN, Minor RR. Canine COL1A2 mutation resulting in C-terminal truncation of pro-alpha2(I) and severe osteogenesis imperfecta. J Bone Miner Res 2001; 16:1147-53. [PMID: 11393792 DOI: 10.1359/jbmr.2001.16.6.1147] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
RNA and type I collagen were analyzed from cultured skin fibroblasts of a Beagle puppy with fractures consistent with type III osteogenesis imperfecta (OI). In a nonisotopic RNAse cleavage assay (NIRCA), the proband's RNA had a unique cleavage pattern in the region of COL1A2 encoding the C-propeptide. DNA sequence analyses identified a mutation in which nucleotides 3991-3994 ("CTAG") were replaced with "TGTCATTGG." The first seven bases of the inserted sequence were identical to nucleotides 4002-4008 of the normal canine COL1A2 sequence. The resulting frameshift changed 30 amino acids and introduced a premature stop codon. Reverse-transcription polymerase chain reaction (RT-PCR) with primers flanking the mutation site amplified two complementary DNA (cDNA) fragments for the proband and a single product for the control. Restriction enzyme digestions also were consistent with a heterozygous mutation in the proband. Type I procollagen labeled with [3H]proline was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Increased density of pC-alpha2(I) suggested comigration with the similarly sized pro-alpha2(I) derived from the mutant allele. Furthermore, a-chains were overhydroxylated and the ratio of alpha1(I):alpha2(I) was 3.2:1, consistent with the presence of alpha1(I) homotrimers. Analyses of COL1A2 and type I collagen were both consistent with the described heterozygous mutation affecting the pro-alpha2(I) C-propeptide and confirmed a diagnosis of OI.
Collapse
Affiliation(s)
- B G Campbell
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | | | | | | |
Collapse
|
15
|
Lim AL, Doyle SA, Balian G, Smith BD. Role of the pro-α2(I) COOH-terminal region in assembly of type I collagen: Truncation of the last 10 amino acid residues of pro-α2(I) chain prevents assembly of type I collagen heterotrimer. J Cell Biochem 1998. [DOI: 10.1002/(sici)1097-4644(19981101)71:2<216::aid-jcb7>3.0.co;2-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|